BODC HEADED DOCUMENT NO.  41614                         
                                                                                
 Applies to BODC Series Ref. Nos.:   29842,  29854,  29866,  29878,  29891,     
                     29909,  29910,  29922,  29934                              
                                                                                
    Aanderaa Pressure Recorder                                                  
                                                                                
    The Aanderaa recorder uses a Digiquartz type 2-300a quartz crystal pressure 
    transducer.  The pressure sensor consists of a convoluted bellows linked to 
    a  40kHz  quartz crystal resonator coupled by piezoelectric  action  to  an 
    electronic resonator. Data are recorded on to 0.25 inch magnetic tape on an 
    Aanderaa  data logger in the same case.  A quartz crystal clock is used for 
    controlling the sampling interval.  The data are recorded as 10 bit  binary 
    words in serial form with the frequency count from the sensor stored as the 
    most and least significant counts.